Critical Care Units and Respiratory Failure

• Critical care units provide care for critically ill patients
• Critical care offers the highest level of care available
• They have different staffing ratios with ICU nursing ratios being 1:1 for each patient
• Critical care units have access to highly specialized staff and equipment (CVVHDF, mechanical ventilation)

Reasons for ICU Admission:

• Single organ failure
• Multi-organ failure such as septic shock
• Planned post-operative admissions(post cardiac surgery)
• Patients who need continuous dialysis (CVVHDF)
• Patients who need cardiac/respiratory support not available on a regular ward, such as vasopressors or ventilation

Pathologies to be Covered:

• Respiratory failure and ARDS
• Renal Failure
• Liver pathology
• Sepsis
• Multi-organ failure
• Burns
• Head injury

Respiratory Failure and ARDS

Respiratory Failure

• The respiratory system fails in one or both of its gas exchange functions:
  • Oxygenation
  • Carbon dioxide elimination

Respiratory Failure Types

• Type I respiratory failure is characterized by low PaO2 (<8kPa), normal PaCO2, and may have occasionnally low PaCO2
• Type II respiratory failure involves low PaO2 (<8 kPa), and high PaCO2 (>7.2 kPa)

Management of Respiratory Failure

• There are two types which incluide
  • Non-invasive
  • Invasive

ARDS

• ARDS(Acute Respiratory Distress Syndrome) is an acute resiratory distress syndrome

• Key feature = Pa02/Fi02 ratio of < 25kPa.

• ARDS also involves inflammation and increased permeability of the alveolar capillary membrane.

• It Results in severe respiratory distress & hypoxemia

• ARDS can cause uneven lung damage which leads to:

  • Undamage
  • Consolidated
  • Fibrotic
  • Collapsed
  • Necrotic

ARDS - Direct and Indirect Causes

• Direct causes:
  • O2 toxicity
  • Pneumonia
  • Aspiration
  • Direct chest trauma
  • Burns
  • Near drowning
  • Inhalation of smoke or toxins
• Indirect causes:
  • Shock
  • Sepsis
  • Cardiopulmonary bypass
  • Pancreatitis
  • Drugs
  • Multiple transfusions

Signs and Symptoms of ARDS

• Symptoms inclide:
  • Acute onset
  • WOB & tachypnoea
  • Cyanosis
  • Tachycardia
  • Auscultation
  • ABGS
• CXR appears normal initially, then shows bilateral infiltrates.
• PaO2/FiO2 < 26
• Bilateral infiltrates on frontal (AP) CXR
• PAWP < 18mmHg.

Treatment for ARDS

• Medical treatment includes:
  • Treatment of the underlying cause
  • Supportive care.
  • Mechanical ventilation with high PEEP
  • Monitoring intravascular volume with Swan Ganz
  • Nitric oxide
  • Prone positioning
  • ECLS
• Physiotherapy:
  • Closed circuit suction due to high PEEP
  • Managing secretions
  • Prone positioning
  • Focus on limb care, ROM, positioning
  • Moving to become more active

ARDS Complications

• Multiple organ system failure
• Pulmonary fibrosis
• Ventilator-associated pneumonia
• Pneumothorax

Cardiac Failure

• Cardiac failure will not covered in detail in ICU lectures as thisis covered in subsequent lectures
• Assessment of cvs system in ICU setting will happen next week

Renal Failure

• Renal Failure results in response to hypotension, hypoxia, or MOF

• The Severity is measured by the underlying condition.

• Renal Failure is biochemically evident when less than 40% of nephrons are working.

• Dialysis is required with less than 10% of nephrons operating.

• Acute Renal Failure may be irreversible, affecting around 30% of critically ill patients.

• Chronic Renal Failure

• Normal urine output = 1ml/kg/hr.

• There is concern if less than 30 mls or 0.5ml/kg/hr output

Renal Failure Types

• Acute Renal Failure:
  • Blood loss
  • Severe burns
  • Kidney stone
  • Multi-organ failure
• Chronic Renal Failure:
  • Diabetes
  • Anything that blocks drainage from kidney
  • Intrinsic renal disease

Issues related to Renal Failure

• Metabolic acidosis
• Uraemia
• Hypertension

Metabolic Acidosis

• H+ ions are bi-products of metabolism
• Kidneys normally excrete H+ and retain HCO3
• Renal disease therefore causes pH to fall
• Compensated by hyperventilation

Uraemia

• Urea is a bi-product of protein breakdown
• Retention of it causes anorexia, nausea, vomiting, lethargy, drowsiness, death
• Uremic myopathy
• Immunosuppression

Hypertension

• Retention of salt and water causes hypertension
• Fluid retention may cause pleural effusion and pulmonary Oedema

Kidney Function Tests - Urinalysis

• Urea and Creatinine, should be present in a urinalysis.
• Protein, Glucose, RBC, WBC, and Ketones, should not be present in a urinalysis.

Dialysis

• Dialysis uses Diffusion across Concentration Gradient
• Continuous Veno-Venous Hemo-Dialysis

Dialysis Access

• Femoral vein catheter
• Central Venous Catheter
• Subclavian vein insertion
• Internal jugular vein insertion

Risks with Dialysis

• Hypotension
• Infection (immunosuppression)
• Electrolyte imbalance
• Bleeding from the access site
• Air embolism
• Cardiac ischemia or arrhythmia
• Hypoxemia

Liver Failure

• The production of Proteins is for blood plasma
• Production of cholestrol
• Function is converting excess glucose into glycogen for storage
• Regulation of bile
• Regulation blood clotting
• Function is processing of hemoglobin

Liver Failure

• Liver Failure leads to hypoxia
• Acute failure leads to MOF
• Disseminated Intravascular Coagulopathy (DIC)
• Kidney failure in 50% of liver failure
• Cirrhosis results from obstruction of the portal vein causing portal hypertension.
• It is also due to medication (paracetamol overdose)

Liver Failure Treatment

• Transplant is the choice of treatment or can lead to oedema and hypotension

Multi-Organ Failure

• Multi-Organ Failure results in system failure caused by direct insult or SIRS.
• It often has multiple causes, often precipitated by shock,
• Hypoperfusion and reperfusion is another variable
• The Main victim is lung > hypoxia.
• It also leads to altered circulatory distribution.

Medical Multi-Organ Failure Management

• Treat sepsis focus
• Restore homeostasis, sustain tissue profusion
• Maintain pH >7.35
• Nutritional support, energy requirements may be >2 normal
• Fluid management to avoid impairment and lung injury
• Antibiotics

Multi-Organ Failure Physiotherapy

• As indicated, depends on underlying cause, limb care; myopathies

Sepsis

• Sepsis is a potentially life-threatening condition caused by the body's response to an infection

Body Response

• Infection occurs when viruses, bacteria, or other microbes enter the body and begin to multiply.
• White blood cells, antibodies, and other mechanisms aim to rid your body of the foreign invader.
• Many symptoms occur during an infection such as fever, malaise, headache, rash because the immune system is eliminate infection
• Bodies respond with fever, heat inactivates many viruses, the secretion of interferon that block viruses from reproducing, using antibodies to engage viruses.
• An overactive and toxic response to infection is known as sepsis
• Sepsis is a medical emergency requiring rapid diagnosis and treatment
• Sepsis is also a secondary response to a primary infection.

Signs of Sepsis

• Meningitis
• Upper respiratory Infection of unknown source
• Pneumonia
• Skin and Soft tissue infection.
• Bloodstream Infection
• Catheter related Infections
• Abdominal Infections
• Urinary Tract Infections
• Appendicitis, Diarrhea or Gallbladder infection

Sepsis

• SIRS can be detected by measuring Temperature, RR, HR, WCC
• 2 SIRS + Confirmed or suspected infection indicates Sepsis
• Sepsis + with end-organ dysfunction, hypotension, or increased lactate defines Severe sepsis
• Septic shock = Severe sepsis w/ persistent hypotension, or Lactate >4mmol

Systemic Inflammatory Response Syndrome is characterized by 2 or more of the following:

• Temp > 38°C or < 36°C
• HR > 90 bpm
• RR > 20 bpm and PaCO2 < 4.3 Kpa
• WCC > 11

Septic Shock Processes

• It causes: -Inadequate tissue perfusion -Anaerobic metabolism -Lactic acidosis -Metabolic acidosis -Cellular damage -Organ failure

Sepsis Pathophysiology

• Inflammation
• Coagulation
• Fibrinolysis All lead to HAEMORRHAGE

Sepsis Symptoms

• Clinical signs:
  • Fever / hypothermia
  • Unexplained tachycardia / tachypnoea
  • Signs of peripheral vasodilation
  • Unexplained shock
  • Changes in mental status
• Haemodynamics:
• Increased O2 consumption
• Lactic acidosis
• Unexplained alteration in renal / hepatic function
• Thrombocytopenia / DIC

Symptoms of sepsis

• Fast heart rate.
• Low blood pressure.
• Fever or hypothermia.
• Shaking or chills.
• Warm or clammy/ sweaty skin.
• Confusion or disorientation.
• Shortness of breath.
• Sepsis rash.
• Extreme pain or discomfort.

Sepsis Management

• Initiate with the "hour-1 bundle" upon recognizing sepsis/septic shock.
• Remeasure lactate if initial lactate is elevated (> 2 mmol/L).
• Obtain cultures before administering antibiotics.
• Administer broad-spectrum antibiotics.
• Begin rapid administration of 30 mL/kg crystalloid for hypotension or lactate ≥ 4 mmol/L
• Apply vasopressors if hypotensive during or after fluid resuscitation to maintain a mean arterial pressure ≥ 65 mm Hg.

Burns

• Burns
• Result from Thermal damage through inhalation of hot gas
• Respiratory complications are the major cause of death following fire entrapment

Causes of burns

• Bronchospasm
• Pulmonary oedema
• Paralysis of cilia
• Ulceration
• Lung tissue burns
• Destruction of surfactant
• Infection
• Lung expansion restricted

Components of smoke inhalation injury

• Thermal injury
• Chemical injury
• System Intoxication

Burns Physiotherapy

• Implications include maintain lung volume
• Clearance of secretions caused by airway damage
• Humidification
• Respiratory manual techniques should not be attempted over chest burns
• Postural drainage is contra-indicated if there is oedema around the head or neck
• Think communication if patient can not speak for patient

Head Injury

• Primary brain injury is irreversible.
• Secondary brain injury can increase mortality risk.
• The brain swells when damaged, peaking at 24 hours post injury.
• This increases ICP which affects Cerebral Perfusion Pressure
• Raised ICP causes secondary brain injury, main aim is to reduce damage
• CPP (driving force of cerebral circulation) = MAP - ICP

Signs of raised ICP

• ICP is the most accurate measure
• Reduced GCS
• Pupils unreactive to light
• Change in pupil size (usually increase)
• Change in vital signs or breathing pattern
• Change in muscle tone
• Vomiting

Factors increasing ICP

• Movement
• Head-down
• Fluid overload (dehydration reduces CPP)
• Coughing, suctioning, MHI, manual techniques
• Hypertension
• Tachycardia
• High PaCO2 – cerebral vasodilation
• Low PaO2 - cerebral vasodilation
• Pain

Head Injury - Management

• Adequate Sedation & ventilation is necessary to prevent raised ICP *
• Intubation - protect airway
• Ventilation manage PaCO2 *
• Monitoring
• Head elevation and maintain neck alignment
• Fluid and Temperature management
• Nutrition
• Drug therapy
• Mechanical ventilation
• Physiotherapy
• If neccessary Surgery
• If neccessary admission to Beaumont : centre for neurosurgery in Ireland for Craniotomy, Craniectomy or Thrombectomy

Transplant

Lung Transplant:

• Used for indicated severe lung disease for which other treatment options are no longer adequate. While it is not a cure; About 55% of lung transplant recipients have a survival rate of at least five years.

Heart Transplant:

• For a failing heart, where medical management is no longer effective
• Indications include: -Dilated Cardiomyopathy,-Ischaemic Cardiomyopathy -Non-Ischaemic Dilated Cardiomyopathy, Hypertrophic Cardiomyopathy -Valvular Heart Disease -Congenital Heart Disease, Univentricular Heart & Pulmonary Atresia etc
• The average patient survival after heart transplant in the UK & Ireland is about 12 years.

Renal Transplant:

• Used for any condition that leads to end stage renal disease
• Typical conditions that will cause it
  • Diabetes
  • Glomerulonephritis
  • Pyelonephritis
  • Polycystic kidney disease
  • Obstructive uropathy
  • Congenital urinary tract abnormalities
• Average life expectancy with Transplant:
  • Living donor: 12-20 years
  • deceased donor: 8-12 years

Liver Transplant:

• Most common indications are liver function
• Indications are liver function deterioration
• Primary and secondary liver cancer

Liver Transplants

• It uses Double subcostal incision & laparotomy
• Pain relief is important post op

Liver Transplants Complications

• Right basal atelectasi
• Pleural effusion
• Liver rejection
• Side effects of immunosuppression

Post Transplant Physiotherapy

• Respiratory assessment and treatment- mainly secretion burden, weaning FiO2, ROM.
• Mobility In ICUedge of bed sit, sit-stand, Transfer to chair, mobilising etc.
• Increasing mobility, re-introducing ADLs
• Pay attention to post-op instructions
• Exercise caution re infection control policies - immunosuppressed post transplant
• ICU assessment – next weeks lecture

Life Post Transplant

• Immunosuppression – heightened risk of infection
• Lifestyle changes
• Medication management
• Side effects from medications
• Risk of organ rejection
• Main aims of transplant:
• Increased survival from the primary disease
• Increase quality of life for the recipient

Post Intensive Care Syndrome

• Causes:

  • Physical: Intensive care unit acquired weakness (ICU-AW)

  • Cognitive: Memory, concentration, fatigue

  • Psychological: Delirium, anxiety, depression

  • Socioeconomic and Family

  • Chronic organ dysfunction

  • Delirium

  • Rapid muscle loss:

• Then combine with:

  • Mechanical ventilation
  • Sedative drug,
  • Neuro muscular blockade (NMB): -Enforced bed rest

Effects of long haul ICU stay lead to death

• Competing priorities eg: acute respiratory/discharges
• More dependent pts get less mobilisation
• Highly influenced by MDT staffing
• Common problems in avoidable deaths after ICU are:
  • Sub optimal rehabilitation (69%)
  • Sub optimal nutrition (41%)

Additional notes

• Different pathologies have different implications for treatment
• Rare to see only one pathology in an ICU population need to understand interactions
• Week lecture will cover: Assessment and ventilation